Causes

In women of child-bearing age, yeast infections due to Candida albicans are particularly common. This yeast normally resides on the skin or in the intestine. From these areas, it can spread to the vagina. Yeast infections are not transmitted sexually. They are common among pregnant women and women who have diabetes. Yeast infections are more likely to occur just before menstrual periods. Yeast infections are also more likely to develop if the immune system is weakened—suppressed by drugs (such as corticosteroids or chemotherapy drugs) or impaired by a disorder (such as AIDS).

Antibiotics taken by mouth tend to kill the bacteria that normally reside in the vagina and that prevent yeast from growing. Thus, using antibiotics increases the risk of developing a yeast infection.

After menopause, yeast infections are uncommon except in women who take hormone therapy.

Symptoms

The vagina and vulva may itch or burn, particularly during sexual intercourse. The genital area may become red and swollen. Women may have a white discharge, often thick and resembling cottage cheese.

Yeast infection symptoms may worsen the week before a menstrual period begins.

Did You Know...

Yeast infections are not sexually transmitted.

Taking antibiotics increases the risk of yeast infections.

Diagnosis

A doctor's evaluation

Examination of a sample of the discharge and/or fluid from the cervix

If women have a vaginal discharge that is unusual or that lasts for more than a few days or have other vaginal symptoms, they should see a doctor.

Doctors suspect a yeast infection based on symptoms, such as a thick, white discharge that often resembles cottage cheese. They then ask questions about the discharge, other symptoms, possible causes (such as diabetes, other disorders, and use of antibiotics or hormones), and hygiene.

To confirm the diagnosis, doctors do a pelvic examination. While examining the vagina, the doctor takes a sample of the discharge with a cotton-tipped swab. The sample is examined under a microscope and sometimes cultured (placed in a substance that allows microorganisms to grow). With this information, the doctor can usually identify the microorganism causing the symptoms. Usually, the doctor also uses a swab to take a sample of fluid from the cervix (the lower part of the uterus that opens into the vagina). This sample is tested for sexually transmitted diseases.

Prevention

Women who are at high risk of a yeast infection may need to take an antifungal drug by mouth to help prevent yeast infections. Such women include those with the following:

Diabetes

A need to take antibiotics for a long time

Repeated yeast infections, particularly in women with a weakened immune system

Treatment

Antifungal drugs

Yeast infections are treated with antifungal drugs. They may be used in the following ways:

Applied as a cream to the affected area

Inserted into the vagina as a suppository

Taken by mouth

Butoconazole, clotrimazole, miconazole, and tioconazole are available without a prescription. Oils in these creams and ointments weaken latex-based condoms (but not diaphragms), so women cannot rely on condoms for birth control.

Antifungal drugs (such as fluconazole and itraconazole) taken by mouth require a prescription. A single dose of fluconazole is as effective as the creams and ointments. However, if infections recur often, women may need to take several doses.

Drugs Used to Treat Vaginal Yeast Infections

Drug

Dosage

Creams or gels, available without a prescription

Butoconazole

A sustained-release cream that is applied once

Clotrimazole

Applied as a cream once a day for 7 to 14 days or for 3 days, depending on the strength (concentration)

Miconazole

Applied as a cream once a day for 7 days or for 3 days, depending on the strength (concentration)

Also available as a vaginal suppository inserted once a day for 7 days, for 3 days, or only once, depending on the strength (concentration)

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